Hair cutting appliances, particularly electric hair cutting appliances, are generally known and may include trimmers, clippers and shavers, for instance. Electric hair cutting appliances may also be referred to as electrically powered hair cutting appliances. Electric hair cutting appliances may be powered by electric supply mains and/or by energy storages, such as batteries, for instance. Electric hair cutting appliances are generally used to shave or trim (human) body hair, in particular facial hair and head hair to allow a person to have a well-groomed appearance. Frequently, electric hair cutting appliances are used for cutting animal hair.
Typically, a blade set of a hair cutting appliance within the context of the present disclosure comprises a blade set arrangement involving a movable cutter blade (also referred to as cutter or cutter blade) and a stationary blade (also referred to as guard). A relative movement, particularly a relative reciprocating movement, between the stationary blade and the cutting blade causes the cutting action.
Typically, the stationary blade is the blade that is closer to the to-be-treated skin/scalp or hair portion than the cutter blade. Frequently, the stationary blade directly contacts the skin or scalp of the person (or animal) whose hair is to be cut. The stationary blade protects the skin against the fast-moving or fast-reciprocating cutter blade. Both the stationary blade and the cutter blade are provided with teeth comprising cutting edges which cooperate to cut hair in a scissor-like action.
U.S. Pat. No. 2,178,669 A discloses a hair clipper comprising having a stationary cutter-head element built up of laminae or plates. Laminae having extended tooth portions are alternated by laminae lacking extended tooth portions.
U.S. Pat. No. 2,096,477 A discloses a hair clipper shearing comb comprising a stack of similar blanks which define both the teeth and the hair receiving spaces between them.
U.S. Pat. No. 6,742,262 B2 discloses a hair clipper comprising a body with a tongue structure pivotally mounted to and supported by said body; a blade assembly detachably securable to said body and having at least a stationary blade and a reciprocating blade, each blade having a cutting edge; an actuator; and a control lever operatively connected to said actuator, wherein when said control lever is rotated, said actuator causes said cutting edge of said reciprocating blade to move relative to said cutting edge of said stationary blade so as to allow the hair cutting length to be adjusted, wherein said blade assembly has a pocket structure with a bracket for selectively and detachably engaging said tongue structure and thereby enabling said blade assembly to be detachably secured to said body.
As a result of this design, a relative position between tips of the movable blade and the stationary blade can be adjusted. This involves an adjustment of the cutting length, provided that the stationary blade is tapered towards the tip. The cutting length is defined by a present distance or spacing between the actually processed scalp or skin and the cutter blade, particularly a plane in which the cutting edges are arranged.
Generally, blade sets involving a stationary blade that cooperates with a movable blade to effect the hair cutting action are made from steel material which also involves that the stationary blades may be integrally shaped parts. In conventional appliances, as disclosed in U.S. Pat. No. 6,742,262 B2, only a slight tapering of the stationary blade, particularly of the teeth thereof, is present. This enables some fine adjustment of the cutting length. A maximum cutting length provided by these conventional blade sets is typically less than 2.0 mm (millimeter).
So as to expand the length adjustment range, so-called attachment combs may be provided which are typically made from plastic material. The attachment combs are placed on top of the stationary blade so as to increase the distance between the skin/scalp and the blade set. Hence, the plastic attachment combs are additional attachment parts that are generally arranged in a detachable fashion. The attachment combs are not involved in the scissor-like cutting action.
As attachment combs are typically detachable, there is a certain losing risk. Further, even though attachment combs are relatively simple parts, there are certain manufacturing costs, assembly costs and logistic expenses as additional separate parts are involved. Further, operating the attachment combs is sometimes experienced as being uncomfortable, cumbersome, and somewhat outmoded.
There is thus still room for improvement in the design of and manufacturing approaches for stationary blades of hair cutting appliances.